8/10/2019 leanM

1/8

In production plants across the globe, lean manufacturing techniques are being

used to meet increasing demands placed on manufacturers. Originally developed

as a methodology to make production processes highly efficient, lean techniques

have been adopted by more than 72 percent of machine shops across the country.

For many of these, the techniques have helped them to dramatically increase their

competitive edge, while continuing to remove wasteful practices and contribute to

the bottom line.

What is lean manufacturing?

Although the basic lean model was introduced more than 100 years ago, it has

continued to evolve over time, from Henry Fords continuous assembly lines for

the Ford Model T, to the concept of interchangeable parts used by Eli Whitneyand Samuel Colt, to the Toyota Production System. These concepts, in addition to

a multitude of others, have come together to formulate what we know today as

lean manufacturing.

The core idea behind lean manufacturing is maximizing customer value while

minimizing waste, thereby achieving manufacturing excellence through the

creation of more value with fewer resources. Waste is defined as an activity that

does not add value to the product. Through the elimination of waste along the

entire manufacturing process, rather than at isolated points, companies are able

to create processes that need less human effort, less space, less capital, and less

time to produce high-quality, lower-cost products compared with traditional

business systems.

Guiding principles of lean

Given the shift toward a customer-centric environment while facing formidable

competition, many manufacturers are implementing lean principles to help

eliminate waste and increase efficiencies rather than relying on processes and

procedures that have been used in the past (figure 1). To help guide companies

through a lean transformation, James Womack and Daniel Jones developed a

five-step thought process detailed in their book,Lean Thinking(Free Press, 2003).

The five steps represent a continuous cycle of improvement, and act as the

foundation for the successful implementation of lean in a facility:

1. Specify value.Identify the value of a specific product from the customers

perspective. Value can only be defined by the ultimate customer, although it must

be created by the producer.

http://www.amazon.com/Lean-Thinking-Corporation-Revised-Updated/dp/0743249275http://www.amazon.com/Lean-Thinking-Corporation-Revised-Updated/dp/0743249275http://www.amazon.com/Lean-Thinking-Corporation-Revised-Updated/dp/0743249275http://www.amazon.com/Lean-Thinking-Corporation-Revised-Updated/dp/0743249275

8/10/2019 leanM

2/8

2. Identify the value stream.Identifying the entire value stream for each

product will almost always reveal three types of actions along the value stream,

including steps that create value, steps that create no value but are unavoidable

with current technologies and production assets, and nonvalue-adding steps that

can be eliminated.

3. Create flow.Once value has been precisely specified and the value stream for

a specific product fully mapped, making work elements flow continuously with

minimal queues and no rework or stoppages is the next step in a lean

transformation.

4. Establish pull.After wasteful steps have been removed, and flow has been

established, the ability to deliver only what is wanted by your customer, and only

when they want it, is the fourth principle of lean thinking: pull. Allowing

customers to pull a product through the process is indicative of the organizations

ability to be responsive to a customers needs.

5. Seek perfection.As organizations bring their processes through the initial

four principlesaccurately specifying value, identifying the value stream and

removing wasteful steps, creating flow, and letting customers pull value from the

enterprisethe fifth principle, perfection, becomes attainable.

Figure 1:Guiding principles of lean

Although there is no such thing as a perfect process, companies can constantly

strive for perfection through the elimination of waste. In the Toyota Production

Systemdeveloped by Taiichi Ohno, Shigeo Shingo, and Eiji Toyodaone of the

major precursors to lean manufacturing, the elimination of waste, is also one of

the main objectives. The Toyota Production System even goes so far as to identify

seven different types of wastes, known as the seven deadly wastes.

Eliminating the seven deadly wastes

8/10/2019 leanM

3/8

The seven deadly wastes of manufacturing are activities that have been identified

as nonvalue-adding events or processes that hinder profitability in a company. All

finished goods and batched inspections include the seven deadly wastes.

However, being cognizant of this fact can help companies eliminate the waste

while achieving maximum efficiencies. Below are the seven deadly wastes and

lean tools that can be implemented to counteract waste.

1. Waiting.Time spent waiting on something, or someone, to complete a task.

Lean tool: Design processes so that flow is continuous, and there are minimal (or

no) buffers between steps in production.

2. Motion.Any unnecessary movement of people that does not add value to the

product or service.

Lean tool: Ensure that work areas are logically organized, e.g., rather than having

a worker walk 20 feet to pick up spare parts every half-hour, minimize the

distance to 5 feet to significantly reduce excess motion.

3. Overprocessing.Using more energy or activity than is needed to produce a

product.

Lean tool: Look for potential simplifications to the manufacturing process, e.g.,

instead of completing 100-percent inspections on parts that never fail, reduce the

number of parts inspected to greatly reduce processing time.

4. Inventories and queues.Excess product waiting to be processed.

Lean tool: Excess or just-in-case inventory can result in lost money and resources

caused by storage. Aiming for just-in-time inventory reduces downtime associated

with inventory problems.

5. Transportation.Unnecessary movement to get goods from one process to

the next.

Lean tool: The transportation of goods or material can be risky. Damages or

delays incurred while goods are in transit uses up resources. Effective planning

can ensure that excess wastes in terms of moving do not occur.

6. Overproduction.Making more parts or information than is required.

Lean tool: Pacing material flow through production to match customer demand

can help to minimize overproduction, and is more cost-efficient in the long run.

7. Fixing defects and mistakes.Time spent repairing or reworking material

or information.

8/10/2019 leanM

4/8

Lean tool: The cost of fixing defects or mistakes is often cheaper the sooner they

are found. For example, mistakes found at raw-materials inspection may cost only

$10 to isolate and fix, whereas fixing a product at the work-in-progress stage may

cost hundreds of dollars.

The lean transformation: Do more with less

Lean is not simply a toolbox, but a total perspective. Undertaking a lean

transformation can be a difficult transition. However, understanding that lean is

not only a set of tools but also a cultural concept that affects every level of an

organization, will result in a successful implementation. From the production

floor to C-level management, it is critical for teams to understand the concept and

buy into the overall goal. Below are four common lean tools and practices

implemented in the process of bringing on a lean transformation.

Cellular manufacturing:Arranging production work stations and equipment

in a sequence that supports a smooth flow of materials and components through

the production process with minimal transport or delay. Shifting from traditional

batch-and-queue mass production systems (figure 2) to a single-piece flow-and-

pull production system (figure 3), cellular manufacturing helps to eliminate

overproduction and reduce defects.

Example: Allowing organizations to be flexible in terms of production setup anddelivery, cellular manufacturing helps to facilitate faster turnaround and reduce

work-in-process inventory, while optimizing the layout on the production floor.

Figure 2:Typical batch-and-queue system

8/10/2019 leanM

5/8

Figure 3:Cellular manufacturing layout

5S workplace organization:A series of activities for eliminating wastes that

contribute to errors, defects, and injuries.

Simplify. Clearly distinguishing what is necessary and disposing of the

unnecessary

Straighten. Organizing the necessary items so that they can be used and returned

easily (figure 4)

Scrub. Cleaning floors, equipment, and furniture in all areas of the workplace.

Stabilize. Maintaining and improving the standards of the first three Ss

Sustain. Achieving the discipline of properly maintaining the correct 5S

procedures and continuously improving to making maintaining 5S easier

Figure 4:These images illustrate 2S: Everything has a proper location and an

organized method of location marking.

In-line inspection:Removing the need for separate testing and inspection labs

(figure 5), in-line inspection allows workers to perform inspections directly on the

line to ensure the accuracy of in-process work. Verifying measurements on the

line, rather than having to bring a part to a separate temperature-controlled

room, helps to create more efficient workflows and streamlines the inspection

process (figure 6).

Example: In a lean work cell, the goal is to eliminate scrap, while building quality

into the process. One way to accomplish this is to implement portable coordinate

measuring machines (CMMs) on the line, increasing production efficiencies and

8/10/2019 leanM

6/8

producing higher quality finished goods. Mounted directly on the machine,

portable CMMs eliminate the need to bring a part to a quality lab, saving the

company time and money. By utilizing portable metrology tools such as

articulating arms designed to withstand harsh working environments, operators

are able to quickly identify defects of parts in-process.

Figure 5:Typical batch manufacturing and inspection

Figure 6:Lean manufacturing and inspection

Kaizen:Often considered to be the building block of all lean production

methods, kaizenevents are rapid and cost-effective projects that focus on

identifying waste, improving productivity, and achieving sustained continualimprovement in targeted activities and processes.

Aiming to involve workers from multiple functions and levels in working together

to address a problem or improve a process, the kaizenteam uses analytical

techniques such as value-stream mapping and the 5 Whys to identify

opportunities quickly to eliminate waste in a targeted process or production area.

Example: After identifying an area for a rapid improvement event, such as a

production area where significant bottlenecks or delays occur, the kaizenteam

must identify the root cause of the problem. This can be accomplished by utilizing

the 5 Whys technique. An example would be:

8/10/2019 leanM

7/8

Why did the machine stop? There was an overload, and the fuse blew.

Why was there an overload? The bearing was not sufficiently lubricated.

Why wasnt it lubricated sufficiently? The lubrication pump was not pumping

sufficiently.

Why wasnt it pumping sufficiently? The shaft of the pump was worn and

rattling.

Why was the shaft worn out? There was no strainer attached and metal scrap got

in.

Once the root cause of the problem has been identified, the team can then work to

collect information on the targeted area, such as measurements of overall product

quality, amount of work-in-progress, and scrap rate and source of scrap.

Analyzing these data allows the team to identify areas for improvement, and test

improvement options before implementation.

A key portion of a kaizenevent is the follow-up activity to ensure improvements

are sustained and not just temporary. Following an event, the team routinely

tracks key performance measures and document improvement gains to assess

performance and identify modifications that may be necessary to sustain the

improvements.

Portable CMMs and lean manufacturing

Ideal for a variety of applications, including 3-D modeling, reverse engineering,

alignment, machine installations, and rapid prototyping, portable coordinate

measuring machines (CMMs) such as articulating arms and laser trackers have

become critical components in the implementation of lean principles. Providing

companies with ways to help streamline inspection processes, create flow, and

eliminate deadly wastes in a lean manufacturing environment, portable CMMs

enable companies to do more with less.

One of the major elements of lean manufacturing is the concept of creating flow.

By making work elements flow continuously with minimal queues and no rework

or stoppages, a company is one step closer to reaching optimal levels of

production. Creating flow through the implementation of portable CMMs on the

line simultaneously eliminates two of the deadly wastes, waiting and

transportation.

For example, by mounting an articulating arm directly on a machine producing a

part, operators are able to create flow between each station and eliminate the

waiting periods commonly found in batch-and-queue manufacturing. Eliminating

the machine outage time necessary for off-line inspection, operators are able to

8/10/2019 leanM

8/8

reduce inspection times without having to transport materials to inspection

rooms while mitigating measurement variability between users.

Fixing defects is another example of a deadly waste that can be helped through

the implementation of portable CMMs. Many companies utilize portable CMMs

for incoming and in-process inspection. For example, by implementing an

articulating arm to inspect parts as they arrive, defects can be eliminated at the

raw materials stage, preventing incorrect products from making it further into the

production process. Additionally, laser trackers can be used for in-process

inspections, ensuring that components are aligned correctly for work-in-process,

eliminating rework at final inspection. Discovering any errors early in the

production process saves companies valuable time and money.

Summary

Many companies have implemented lean manufacturing techniques to create

more efficient workflows. Through the elimination of waste and the creation of

flow through the various processes, companies are able to eliminate costly scrap

and rework while contributing to their bottom line.

Implementing portable CMMs into standard workflows has helped them achieve

their lean manufacturing goals; in many cases, companies that have implemented

portable CMMs directly on the line for in-process inspections have seen a

reduction in inspection time of up to 60 percent. Used to ensure accurate

alignment and precision measurements, portable CMMs have become a value-

adding component helping companies to achieve various lean principles.